Data Input Device

1. A data input device comprising: an illuminator operative to illuminate at least one engagement surface; a two-dimensional imaging sensor viewing said at least one engagement surface from a location outside said at least one engagement surface for sensing engagement of a data entry object with said at least one engagement surface; and a data entry processor receiving an output from said two-dimensional imaging sensor and providing a data entry input to utilization circuitry, said data entry processor employing shadow analysis, said data entry processor comprising the following functionality: as each pixel value is acquired, determining, using the pixel coordinates, whether that pixel lies within a predefined keystroke region and within predefined left and right keystroke subregions therewithin; acquiring pixel values for various pixel coordinates; obtainining the derivative of each pixel value along an X axis; summing said derivatives for each said subregion; subtracting the summed derivatives for the two subregions in each keystroke region, one from the other to provide a difference; comparing said difference with a current key actuation threshold; if the difference exceeds the key actuation threshold for a given keystroke region in a given frame and in the previous frame the pixel total did not exceed the key actuation threshold for that keystroke region, providing a key actuation output; and if the difference does not exceed the key actuation threshold for a given keystroke region in a given frame and in the previous frame the pixel total did exceed the key actuation threshold for that keystroke region, providing a key deactuation output.

2. A data input device according to claim 1 and wherein: said illuminator comprises a non-point light source; and said data entry processor employs a shadow density analyzer to determine the sharpness of edges of a shadow defined by said non-point light source and said data entry object on said at least one engagement surface, which indicated the propinquity of the data entry object to said at least one engagement surface.

3. A data input device according to claim 1 and wherein: said illuminator comprises a plurality of light sources; and said data entry processor employs a shadow coalescence analyzer to determine the extent of coalescence of shadows defined by said plurality of light sources and data entry object on said at least one engagement surface, which indicated the propinquity of the data entry object to said at least one engagement surface.

4. A data input device according to claim 1 and wherein said determining employs a pixel index table which indicates for each pixel, whether that pixel lies within a predetermined keystroke region and, if so, within which keystroke region as well as within which keystroke subregion it lies.

5. A data input device according to claim 4 and wherein said pixel total is maintained for each keystroke subregion in a keystroke subregion accumulator table.

6. A data input device according to claim 1 and wherein said pixel total is maintained for each keystroke subregion in a keystroke subregion accumulator table.

7. A data input device according to claim 1 and wherein said comparing employs a keystroke region threshold table.

8. A data input device according to claim 1 and wherein at least said at least one engagement surface is associated with a pull-down tray in a vehicle.

9. A data input device according to claim 8 and wherein said pull-down tray defined and engagement surface which is configured by projection.

10. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator are associated with a camera.

11. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor detector and illuminator are associated with a home entertainment system.

12. A data input device according to claim 11 and wherein said at least one engagement surface overlies a television screen forming part of said home entertainment system.

13. A data input device according to claim 1 and wherein at least said at least one engagement surface is associated with a table.

14. A data input device according to claim 1 and wherein at least said at least one engagement surface is associated with a remote control device.

15. A data input device according to claim 1 and wherein at least said at least one engagement surface is located within a restricted particulate matter environment.

16. A data input device according to claim 1 and wherein at least said at least one engagement surface is located within an industrial environment unsuitable for a conventional keyboard.

17. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator are associated with a video projector.

18. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator are associated with a restaurant patron interface system.

19. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator are associated with a mobile audio player.

20. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator provide touch screen functionality.

21. A data input device according to claim 20 and wherein said touch screen functionality employs a video display screen.

22. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator provide access control functionality.

23. A data input device according to claim 1 and wherein at least said at least one engagement surface is associated with a game board.

24. A data input device according to claim 23 and wherein said game board defines an engagement surface which is configured by projection.

25. A data input device according to claim 1 and wherein at least said at least one engagement surface is associated with a musical instrument.

26. A data input device according to claim 25 and wherein said musical instrument defines an engagement surface which is configured by projection.

27. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator provide vehicle telematics functionality.

28. A data input device according to claim 27 and wherein said vehicle defines and engagement surface which is configured by projection.

29. A data input device according to claim 1 and wherein at least said two-dimensional imaging sensor and said illuminator provide automatic vending user interface functionality.

30. A data input method comprising: illuminating at least one engagement surface; viewing said at least one engagement surface with a two-dimensional image sensor form a location outside said at least one engagement surface for sensing engagement of a data entry object with said at least one engagement surface; and processing an output from said two-dimensional imaging sensor and providing a data entry input to utilization circuitry, said processing employing shadow analysis, said processing comprising; as each pixel value is acquired, determining, using the pixel coordinates, whether that pixel lies within a predefined keystroke region and within predefined left and right keystroke subregions therewithin; acquiring pixel values for various pixel coordinates; obtaining the derivative of each pixel value along an X axis; summing said derivatives for each said subregion; subtracting the summed derivatives for the two subregions in each keystroke region, one from the other to provide a difference; comparing said difference with a current key actuation threshold; if the difference exceeds the key actuation threshold for a given keystroke region in a given frame and in the previous frame the pixel total did not exceed the key actuation threshold for that keystroke region, providing a key actuation output; and if the difference does not exceed the key actuation threshold for a given keystroke region in a given frame and in the previous frame the pixel total did exceed the key actuation threshold for that keystroke region, providing a key deactuation output.

31. A data input method according to claim 30 and wherein: said illuminating comprises a non-point light source; and said processing employs a shadow density analyzer to determine the sharpness of edges of a shadow defined by said non-point light source and said data entry object on said at least one engagement surface, which indicates the propinquity of the data entry object to said at least one engagement surface.

32. A data input method according to claim 30 and wherein: said illuminating comprises a plurality of light sources; and said processing employs a shadow coalescence analyzer to determine the extent of coalescence of shadows defined by said plurality of light sources and data entry object on said at least one engagement surface, which indicates the propinquity of the data entry object to said at least one engagement surface.

33. A data input method according to claim 30 and wherein said determining employs a pixel index table which indicates for each pixel, whether that pixel lies within a predetermined keystroke region and, if so, within which keystroke region as well as within which keystroke subregion it lies.

34. A data input method according to claim 33 and wherein said pixel total is maintained for each keystroke subregion in a keystroke subregion accumulator table.

35. A data input method according to claim 30 and wherein said pixel total is maintained for each keystroke subregion in a keystroke subregion accumulator table.

36. A data input method according to claim 30 and wherein said comparing employs a keystroke region threshold table.

37. A data input method according to claim 30 and wherein at least said at least one engagement surface is associated with a pull-down tray in a vehicle.

38. A data input method according to claim 37 and wherein said pull-down tray defines an engagement surface which is configured by projection.

39. A data input method according to claim 30 and wherein said illuminating and said sensing are associated with a camera.

40. A data input method according to claim 30 and wherein said illuminating and said sensing are associated with a home entertainment system.

41. A data input method according to claim 40 and wherein said at least one engagement surface overlies a television screen forming part of said home entertainment system.

42. A data input method according to claim 30 and wherein at least said at least one engagement surface is associated with a table.

43. A data input method according to claim 30 and wherein at least said at least one engagement surface is associated with a remote control method.

44. A data input method according to claim 30 and wherein at least said at least one engagement surface is located within a restricted particulate matter environment.

45. A data input method according to claim 30 and wherein at least said at least one engagement surface is located within an industrial environment unsuitable for a conventional keyboard.

46. A data input method according to claim 30 and wherein said illuminating and said sensing are associated with a video projector.

47. A data input method according to claim 30 and wherein said illuminating and said sensing are associated with a restaurant patron interface system.

48. A data input method according to claim 30 and wherein said illuminating and said sensing are associated with a mobile audio player.

49. A data input method according to claim 30 and wherein said illuminating and said sensing provide touch screen functionality.

50. A data input method according to claim 49 and wherein said touch screen functionality employs a video display screen.

51. A data input method according to claim 30 and wherein said illuminating and said sensing provide access control functionality.

52. A data input method according to claim 30 and wherein at least said at least one engagement surface is associated with a game board.

53. A data input method according to claim 52 and wherein said game board defines an engagement surface which is configured by projection.

54. A data input method according to claim 30 and wherein at least said at least one engagement surface is associated with a musical instrument.

55. A data input method according to claim 54 and wherein said musical instrument defines an engagement surface which is configured by projection.

56. A data input method according to claim 30 and wherein said illuminating and said sensing provide vehicle telematics functionality.

57. A data input method according to claim 56 and wherein said vehicle defines an engagement surface which is configured by projection.

58. A data input method according to claim 30 and wherein said illuminating and said sensing provide automatic vending user interface functionality.